jboyle0128

I have a 2021 Chevy 1500 Duramax LTZ and tow a lot, usually around 7k lbs. The truck does great but the other day it was really windy and I had a MIL pop up. I checked the codes on my CTS3 monitor and it showed a P0700 and a P281B. I cleared the codes and all was good. Almost a week later I pulled onto a 50mph zone and cruised for about a mile when I came to a stop light. As soon as I let off the gas pedal it sounded like baseball cards in bicycle spokes. I wasn't towing so I immediately pulled over to the shoulder. The noise was coming from under the cab/dash area. Sounded like rod knock but at a faster speed. It drove normal, just embarrassingly noisy. I dropped it off at Molle Chevrolet in Blue Springs, MO. They've had it for 6 days and claim it's an engine wiring issue. He's had two techs look at it. I don't believe a word he is saying. My vehicles, like a lot of people in this forum, don't go to the dealer unless it's a warranty issue. Both codes are transmission codes so how can it be an engine wiring issue. He told me on the phone it runs rough. It doesn't run rough, just loud. I'll give him another chance to redeem himself or prove me wrong. Otherwise I'm taking it somewhere else. I posted this because my symptoms match Baker 5 to a T. Thanks for letting me rant Jamie

I have 15k miles on my '21 LM2 Duramax Crewcab Z71. I installed the CTS3 monitor so I can watch exhaust temps, boost, EGTs, and a million other parameters. The exhaust note does change when it goes into a regen. It gets lower and almost throaty. If I am towing heavy (7k plus)then it will do a regen every 240ish miles. The CTS3 tells me exactly how many miles since last regen. No towing and a mix of city/hwy driving it goes about 620 miles between regens. The truck is phenomenal on fuel. I average an easy 23mpg (hand calc) with no towing, but I don't baby it and run with traffic. Hand calculated always shows better than the dash mpg number, usually by half to one mpg. We took a trip from KC to Omaha and averaged 28.4mpg with the cruise set at 79. When I tow my 8.5x20 enclosed I usually get 11 to 12mpg. And that's with a Jeep, generator, fuel jugs, tools, probably 8k lbs behind the truck. Again not hypermiling or anything. The cameras make towing a breeze. Never again will I tow a camper or enclosed trailer without the transparent trailer camera setup. Saves my marriage every trip.